I have google this question, but mostly found old questions and answers. Sure in 2014 you can sort photos by title?

I am doing a 365 challenge, and am naming my photos as Day 001 - Some Title, Day 002 - Other Title, etc. I keep the photos on 500px, which generates a random file name (using the 500px plugin to sync to lightroom). So the title only goes in the Title field. But when I look in my 500px/365 collection things are out of order, and there doesn't seem to be any way to sort by 'Title'.

This seems like such a trivial problem for a photo organization tool, I must be missing something....

Once you have uploaded the files to 500px the sort order are most likely controlled by gallery options at 500px.

Or at least that is how the LR plugin works with Zenfolio:

Zenfolio allows me to choose either upload order, by date, title and manual for sorting in their galleries. I would look at your sort options within the galleries at 500px to correct your sort order problems. Other than the 'upload order' choice changing a sort order within Lightroom does not change anything after they have been uploaded. I can change order online but LR plugin does not see the changes/care unless there is a move or deletion.

500px sorts them fine on their website. The 500px exporter uses the Title as the title on 500px, and 500px.com sorts by title by default. The problem is LR does not sort by title, so the photos appear in a different order when in LR vs on the web. This problem is solved if LR can sort by Title.